Hello, On the newly installed honeycomb machines, some Cuirass remote-worker process freeze completely and stop communicating with the remote-server. This has already been observed, but is for some reason more repeatable on those machines. Here are the information I could collect on such a frozen process using GDB: --8<---------------cut here---------------start------------->8--- (gdb) attach 5660 ;frozen cuirass-remote-worker PID (gdb) info thr Id Target Id Frame * 1 Thread 0xffffafd32e20 (LWP 5660) "yHg3r3fS" 0x0000ffffafb3fa80 in do_futex_wait.constprop () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libpthread.so.0 2 Thread 0xffffa6c1c1d0 (LWP 5666) "ZMQbg/Reaper" 0x0000ffffaf7ec294 in epoll_pwait () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libc.so.6 3 Thread 0xffffaf0071d0 (LWP 5667) "ZMQbg/IO/0" 0x0000ffffaf7ec294 in epoll_pwait () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libc.so.6 4 Thread 0xffffa641b1d0 (LWP 5674) "yHg3r3fS" 0x0000ffffaf7b9d04 in clock_nanosleep@@GLIBC_2.17 () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libc.so.6 (gdb) bt #0 0x0000ffffafb3fa80 in do_futex_wait.constprop () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libpthread.so.0 #1 0x0000ffffafb3fb78 in __new_sem_wait_slow.constprop.0 () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libpthread.so.0 #2 0x0000ffffafb80318 in GC_stop_world () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #3 0x0000ffffafb6c020 in GC_stopped_mark () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #4 0x0000ffffafb6c8dc in GC_try_to_collect_inner () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #5 0x0000ffffafb6d598 in GC_collect_or_expand () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #6 0x0000ffffafb73b4c in GC_alloc_large () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #7 0x0000ffffafb74038 in GC_generic_malloc () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #8 0x0000ffffafb74298 in GC_malloc_kind_global () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #9 0x0000ffffafc11fa8 in scm_make_bytevector () from /gnu/store/7g3nbnf2kf31jk696k0nyz9ck55b11a0-guile-3.0.7/lib/libguile-3.0.so.1 #10 0x0000ffffacacc418 in ?? () #11 0x0000ffffacc2ef2c in ?? () (gdb) thr 4 [Switching to thread 4 (Thread 0xffffa641b1d0 (LWP 5674))] #0 0x0000ffffaf7b9d04 in clock_nanosleep@@GLIBC_2.17 () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libc.so.6 (gdb) bt #0 0x0000ffffaf7b9d04 in clock_nanosleep@@GLIBC_2.17 () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libc.so.6 #1 0x0000ffffaf7bf55c in nanosleep () from /gnu/store/cb88z63hyg1icd2kkahiink2p291mhr2-glibc-2.31/lib/libc.so.6 #2 0x0000ffffafb7e844 in GC_lock () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #3 0x0000ffffafb7ecdc in GC_do_blocking_inner () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #4 0x0000ffffafb73998 in GC_with_callee_saves_pushed () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #5 0x0000ffffafb79654 in GC_do_blocking () from /gnu/store/jsda4njqwjp4kb60fwa7n4mlfi1aanpq-libgc-7.6.12/lib/libgc.so.1 #6 0x0000ffffafc96d94 in scm_without_guile () from /gnu/store/7g3nbnf2kf31jk696k0nyz9ck55b11a0-guile-3.0.7/lib/libguile-3.0.so.1 #7 0x0000ffffafc97050 in scm_std_select () from /gnu/store/7g3nbnf2kf31jk696k0nyz9ck55b11a0-guile-3.0.7/lib/libguile-3.0.so.1 #8 0x0000ffffafc97b5c in scm_std_sleep () from /gnu/store/7g3nbnf2kf31jk696k0nyz9ck55b11a0-guile-3.0.7/lib/libguile-3.0.so.1 #9 0x0000ffffafc75918 in scm_sleep () from /gnu/store/7g3nbnf2kf31jk696k0nyz9ck55b11a0-guile-3.0.7/lib/libguile-3.0.so.1 #10 0x0000ffffa6c50d94 in ?? () #11 0x0000ffffacc2ee0c in ?? () --8<---------------cut here---------------end--------------->8--- So the threads 2 and 3 are managed internally by ZMQ. The threads 1 and 4 are respectively the thread pinging the remote-server and the thread actually building stuff. Looks like they are both stuck doing GC stuff. Thanks, Mathieu